OpenPower was the name of a range of servers in the System p line from IBM. They featured IBM's POWER5 CPUs and run only 64-bit versions of Linux. IBM's own UNIX variant, AIX is not supported since the OpenPower servers are not licensed for this operating system.
There were two models available, with a variety of configurations.
Before 2005, OpenPower belonged to the eServer product line. These models have been rolled back into the current IBM System p product portfolio.